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Hi all,
I have investigated a little deeper the problem... Indeed, on Windows platform, the number of mipmaps returned by osg::Image::computeNumberOfMipmapLevels( s, t, r ) is wrong, but it is correct on Linux platforms for the same dds file... Here is attached a little test program that explains why (it is more or less a computeNumberOfMipmapLevels with s=t=1024 and r=1), and it is not linked to OSG. Compile it on Windows 32 bits (works on Win7 and WinXP) (g++ main.cpp -o main.exe) You will see the following result : logf(wf) = 6.93147182464599609375 log(wd) = 6.93147180559945308431 logf(2.0f) = 0.69314718246459960938 log(2.0) = 0.69314718055994528623 logf(wf)/logf(2.0f) = 10.00000000000000000000 log(wd)/log(2.0) = 10.00000000000000000000 floor(logf(wf)/logf(2.0f)) = 9.00000000000000000000 -> Here is the error, it should be 10 too... floor(log(wd)/log(2.0)) = 10.00000000000000000000 floor(testf) = 10.00000000000000000000 floor(testd) = 10.00000000000000000000 Replacing the include of math.h by cmath results in : logf(wf) = 6.93147182464599609375 log(wd) = 6.93147180559945308431 logf(2.0f) = 0.69314718246459960938 log(2.0) = 0.69314718055994528623 logf(wf)/logf(2.0f) = 10.00000000000000000000 log(wd)/log(2.0) = 10.00000000000000000000 floor(logf(wf)/logf(2.0f)) = 10.00000000000000000000 floor(log(wd)/log(2.0)) = 10.00000000000000000000 floor(testf) = 10.00000000000000000000 floor(testd) = 10.00000000000000000000 Under Linux both solutions give the second results. The problem is that osg/Math includes math.h and not cmath. I don't know which would be the best solution :
Up to the list to give the answer... PS : this is also the solution to the discussion "osgPlugins :
dds problem on windows platform" I launched 07/03/2011 Cheers, Christian Schulte Le 20/12/2012 15:15, Lukasz Izdebski a écrit : Hi, i probably have solution for this problem, i have found a bug in dds plugin ReaderWriterDDS.cpp Line 633 unsigned numMipmaps = osg::Image::computeNumberOfMipmapLevels( s, t, r );when compute numMipmaps returns wrong number. this number is less then number of mipmaps in dds file( ddsd.dwMipMapCount ) . This bug makes that when dds mipmaps are loaded to opengl last mipmap (4x4) isn't loaded. and with combination with LINEAR_MIPMAP_LINEAR make this bug. the numMipmaps should be taken form ddsd.dwMipMapCount in attachment i send a corrected version of file. ... Thank you! Cheers, Lukasz ------------------ Read this topic online here: http://forum.openscenegraph.org/viewtopic.php?p=51653#51653 Attachments: http://forum.openscenegraph.org//files/readerwriterdds_204.cpp _______________________________________________ osg-users mailing list [email protected] http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org |
#include <math.h>
#include <stdio.h>
#include <iostream>
using namespace std;
int main(int argc, char** argv)
{
double wd=1024.0;
float wf=1024.0;
cout.precision(20);
cout.setf(ios::fixed,ios::floatfield);
cout<<"logf(wf) = "<<logf(wf)<<endl;
cout<<"log(wd) = "<<log(wd)<<endl;
cout<<"logf(2.0f) = "<<logf(2.0f)<<endl;
cout<<"log(2.0) = "<<log(2.0)<<endl;
cout<<"logf(wf)/logf(2.0f) = "<<logf(wf)/logf(2.0f)<<endl;
cout<<"log(wd)/log(2.0) = "<<log(wd)/log(2.0)<<endl;
cout<<"floor(logf(wf)/logf(2.0f)) = "<<floor(logf(wf)/logf(2.0f))<<endl;
cout<<"floor(log(wd)/log(2.0)) = "<<floor(log(wd)/log(2.0))<<endl;
float testf = logf(wf)/logf(2.0f);
double testd = log(wd)/log(2.0);
cout<<"floor(testf) = "<<floor(testf)<<endl;
cout<<"floor(testd) = "<<floor(testd)<<endl;
return 0;
}
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